B for the Brain

People taking high doses of B vitamins had less brain shrinkage than those who didn't in this Oxford University study.

A new study from Oxford University finds that the B vitamin family — including folic acid, B6 and B12 — may help prevent brain shrinkage that is linked to cognitive decline and Alzheimer’s disease.

Brain atrophy is a serious reality of aging and affects many seniors. It is linked to mild cognitive impairment (MCI), which itself affects 16% of the elderly, and is a risk factor for developing more severe cognitive deficits. In fact, 50% of those suffering from MCI go on to develop full-blown Alzheimer’s, according to the study, which was published in the free journal PLoS ONE.

People who took the B vitamins had significantly less brain shrinkage than those taking placebo: on average, the participants’ brains shrank by 0.76% and 1.08%, respectively. Though this may not sound like a big difference, the brains of people taking B vitamins shrank 30% less than those on placebo.

The current study gave MRI brain scans to 168 people over 70 years old to measure the size of their brains. All participants suffered from MCI at the beginning of the study. After this was done, they split the participants into two groups: one received mega-doses of the B vitamins mentioned above and the other group received placebo. (It’s important to note that the doses contained many times the recommended daily intake of each of the B vitamins.) Participants took their respective treatments for two years, at which point their brains were rescanned and they took a test for cognitive function.

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The researchers, led by A. David Smith, found that people who took the B vitamins had significantly less brain shrinkage than those taking placebo: on average, the participants’ brains shrank by 0.76% and 1.08%, respectively. Though this may not sound like a big difference, the brains of people taking B vitamins shrank 30% less than those on placebo.

People with more brain shrinkage at the end of the trial also performed more poorly on the tests measuring cognitive function.

B vitamins are known to lower the amount of homocysteine in the blood, which has already been linked to Alzheimer’s disease. In fact, Smith and his team write that people who started out with higher levels of homocysteine had less brain atrophy in the end. They add that in the future, more studies will need to determine "if the same treatment will delay the development of Alzheimer's disease" itself, in addition to brain atrophy alone.

Though the doses used in the study were very high, it’s important to get the daily recommended intake of the B vitamin family. Many foods are fortified with B vitamins, and they are typically included in daily multi-vitamin supplements. Be sure to check with your doctor before adding any kind of supplements to the diet.